We found one dictionary that defines the word true warblers:

General (1 matching dictionary)

1. true warblers: Vocabulary.com

(Note: See true_warbler as well.)

Definitions from WordNet (True warbler) ▸ noun:  small active brownish or grayish Old World birds ▸ Also see true_warbler ▸ Words similar to true warblers ▸ Usage examples for true warblers ▸ Idioms related to true warblers ▸ Wikipedia articles (New!) ▸ Words that often appear near true warblers ▸ Rhymes of true warblers ▸ Invented words related to true warblers